Tuesday, July 8
Darling, who has been on the umpire's disabled list for the entire 2014 season, has been a crew chief since 2004 and was officially appointed to National League's officiating staff in 1988.
The 56-year-old San Francisco native worked a pair of All-Star Games (1993, 2003), five League Championship Series (1992, 2004, 2006, 2011-12) and two World Series (2003, 2010) during his professional tenure.
Wolcott, 28, has worked at the Triple-A level since 2011. He made his major- league debut on May 27, 2013 and has logged 149 games of MLB experience.